1. Field of the Invention
The present invention relates to an adapter by which a metal encapsulated implantable cardiac pacer can be converted to an externally worn cardiac pacer. The adapter includes a housing within which an implantable cardiac pacer can be secured by an electrically conductive spring-clip member. The housing includes a plurality of conductive chuck assemblies for electrically connecting a temporary pervenous lead assembly to the cardiac pacer secured within the housing. With this adapter, a physician can try various cardiac pacers before selecting the most appropriate implantable cardiac pacer model to meet the cardiac pacing needs of a patient and before the implantation of any particular cardiac pacer.
2. Description of the Prior Art
Heretofore various enclosure systems and connector systems for implantable cardiac pacers have been proposed. Examples of such previously proposed enclosure systems and connector systems are disclosed in the following U.S. patents:
______________________________________ U.S. Pat. No. PATENTEE ______________________________________ 4.243,042 Ware 4.248,237 Kenny 4,314,562 Ware 4,347,849 Congdon 4,423,732 Tarjan et al. ______________________________________
The Ware U.S. Pat. Nos. 4,243,042 and 4,314,562 disclose an enclosure system for a body implantable electrical stimulator which includes a stimulator enclosure which is formed of first and second preformed members having a generally circular configuration. A cup is also provided into which the components of a body implantable electrical stimulator may be assembled, the cup being configured to fit within the preformed electrical stimulator enclosure. The components of the electrical stimulator are secured within the cup by an encapsulating material which substantially fills the cup, or by elements which engage one or more components to mechanically maintain them in position.
The Kenny U.S. Pat. No. 4,248,237 discloses a case for implantation into a human or animal body comprising two molded plastic chamber members which mate to define a complete chamber. One of the plastic chamber members includes a socket member which is connected to an electronic system. The electronic system comprises a pacemaker and a battery which are housed within the complete chamber.
The Congdon U.S. Pat. No. 4,347,849 discloses a connector system which is used with an external cardiac pacer and which provides an electrical connection to an associated pacer lead assembly. The system includes a pair of terminal blocks each having a bore for receiving a respective connector pin of the lead assembly. A pair of locking plates are pivotally mounted in wedge shaped recesses in the connector blocks. Each plate has an aperture through which the connector plates extend. The locking plates are spring biased into engagement with the connector pins to prevent inadvertent removal of the pins from the bores. An operator actuated release button can be operated to pivot the locking plates from engagement with the pins to enable the pins to be removed from the pacer.
The Tarjan et al. U.S. Pat. No. 4,423,732 discloses a sterile connector system for a packaged pacer that permits testing and use of a pacer while it remains sealed in a sterile container.
As will be described in greater detail hereinafter, the adapter of the present invention differs from the various enclosure systems and connector systems for implantable cardiac pacers previously proposed by providing a housing having an electrically conductive spring-clip member within the housing which acts as an anode connector and which secures an implantable cardiac pacer within the housing in an electrically conductive manner. The housing has two or more conductive chuck assemblies mounted thereon for establishing an electrical connection of the electrical conductors of a temporary pervenous lead assembly to a pacer within the housing. By providing a housing within which a pacer can be secured and to which a temporary pervenous lead assembly can be connected, a physician can try a number of pacers before selecting an appropriate implantable cardiac pacer model to meet the pacing needs of a patient and before implantation of the appropriate cardiac pacer.